One way to keep them from doing this is to get them emotionally-involved in a project with a positive spin, and management may appreciate this suggestion from you.

Believe it or not, there is actually a project where a group collects, sanitizes, remolds and thus recycles partially-used hotel soap bars and ships them to Africa to aid in sanitation.

It seems to me that the product itself (soap) is inexpensive enough that it isn't worth the effort and expense to recycle it and more importantly to ship it, but it seems that these folks are doing exactly that.

There is a list on their web site of their over 1000 participating hotels, and it appears that the JW Marriott hotel in the San Antonio Hill Country, Texas, was their biggest contributor last year, shipping them 9000 pounds of soap.

Apparently, the participating hotels just work with their housekeeping staff to reclaim the soap bars and store them in housekeeping until a sufficiently-efficent sized batch of soap is ready to send.

This really is a good way to encourage the staff to save and recycle the soap, rather than flushing.

I picked up a hotel trade magazine some years ago when I was a road warrior. In it was an ad for a machine that would chew up the soap, sort of like a giant blender. The soap could then be used in the hotel laundry for washing linens. Better than toilet diving any time.